Gareth Southgate says his England side remain “a work in progress” and warned they “won’t become Spain in eight months” after they qualified for next summer’s World Cup in Russia.
Harry Kane’s stoppage-time goal saw off Slovenia on Thursday but England were poor at a subdued Wembley.
Southgate said: “This team has potential but we have a hell of a lot of work to do.
“It’s blindingly obvious we could have played better – but we are there.”
Southgate has guided his team to an expected qualification – their sixth World Cup in a row, equalling England’s best run – after taking over from Sam Allardyce in November.
His side have dropped just four points in the whole campaign but were flat at Wembley until Kane continued his hot scoring streak with a 14th goal in nine games for club and country.
When England travel to Russia, it will be 52 years since the 1966 World Cup victory on home soil. However, Spain – who Southgate chose to reference – won three major tournaments back to back between 2008 and 2012.
The 47-year-old said: “Tonight highlighted where we are. Of course we’d have liked to have played more fluidly and scored more goals.
“It is a work in progress and when I was given the job the aim was to qualify for the World Cup. As a young team having to deal with the expectation and criticism of their performances, it is tough for them.
“They are giving everything they’ve got. They don’t have Champions League winning medals between them.
“In the end, it’s crucial for English football to be at the World Cup.”
Official preparations for next year’s trip to Russia can now start – but England have just one win at a World Cup finals since 2006.
A kind draw on 1 December would help, but Southgate – who went to World Cups as a player in 1998 and 2002 – is aware that expectations will rise despite a poor showing on Thursday.
“The players are suffering the consequences of 25 years, 30 years, 40 years, or whatever – but that isn’t their fault,” he said.
“We have to give them the backing to go and believe.
“It’s the nature of playing for England and managing England. We’re a country of high expectations.
“I’ve seen Bobby Robson get to a World Cup semi-final in 1990 and get hammered up until the quarter-final stage. I can rationalise it all.”
‘Nothing to fear from England’ – analysis
BBC chief football writer Phil McNulty
Southgate acknowledged the level of discontent that swept around Wembley during this abject display by his side.
Southgate accepted it was up to his England players to transform Wembley into a “cauldron” – but this was more like throwing a bucket of ice cold water over any sense of optimism surrounding their aspirations at the World Cup in Russia next summer.
Yes, England achieved the goal of qualification. Yes, England got the win they wanted thanks to Kane’s goal deep into injury time.
And yes, Southgate’s side sent a message out to any opponents waiting to meet them next summer. The problem is the message this game sent out was: “You have nothing to fear from England.”
Southgate rightly made the point that this is a work in progress and it would be hugely unjust to saddle him with the baggage of previous failures, such as the embarrassment of an exit to Iceland in the last 16 of Euro 2016.
The immediate problem, however, is that the countdown to the 2018 World Cup starts now and England look well short of coming anywhere near sides who have ambitions of making their mark in Russia.
England’s central midfield is plodding in the extreme, lacking inspiration and their defence still looks like it would be vulnerable to high-class opposition.
Southgate possesses quality in attack but the mediocrity delivered in front of a cynical and at times sarcastic Wembley gallery was a sad reflection on England’s current status.
Follow Match of the Day on Instagram for the best photos from the world of football.